docs: def _file_not_empty(tmpfile):
          """
          Returns True if file exists and it is not empty
          to check if it is time to read container ID from cidfile
          :param tmpfile: str, path to file
          :return: bool, True if container id is written to the file
          """
          if os.path.exists(tmpfile):
              return os.stat(tmpfile).st_size != 0
          else:
              return False